1. Field of Invention
The present invention relates to an electronic apparatus. More particularly, the present invention relates to an electronic apparatus with an electrostatic discharging structure.
2. Description of Related Art
The keypad or keyboard has become an important communication component between an electronic apparatus and a user. Because the keypad enables quick and convenient input, it has been widely applied to many systems, including personal computers, mobile phones and electronic dictionaries.
It do not have many problems in using the key in the past since the key structure has not been very complex. However, because electronic products nowadays are becoming so miniaturized with advances in manufacturing techniques, problems in using the key are gradually appearing. One of these problems is vulnerability to electrostatic damage.
FIG. 1 shows the structure of a conventional electronic apparatus 100. The structure includes a key cap 102 and a switch component 104. The key cap is used to be an interface touched by a user; therefore, the key cap has a flat surface on the top in general. The key cap 102 is installed on the switch component 104 mounted on a circuit board 106 such as a printed circuit board (PCB), wherein the switch component 104 may be a push-button switch. An electronic component 108 is further disposed on the circuit board 106.
According to fundamentals of electrical science, the human body generally holds some electrostatic charge. The transfer of this electrostatic charge into the electronic apparatus 100 when a user touches the key cap 102 is hard to avoid. Moreover, the surface of the key cap 102 may be coated with a metal layer by an electroplating or sputtering process for aesthetics and durability, but this accelerates the electrostatic charge transfer into the electronic apparatus 100.
According to the foregoing description, the spatial volume of advanced electronic products is decreasing and the density of their electronic components is increasing; therefore, the electronic component 108 is easily penetrated and damaged by the electrostatic charge transferring into the electronic apparatus 100. As shown in FIG. 1, when the user touches the surface of the key cap 102, the electrostatic charge on the body of the user will transfer along a discharge path 110 and pass through and possibly damage the component 108 on the circuit board 106.
The conventional method used for preventing the above-mentioned phenomenon is to obstruct the electrostatic charge transfer to other electronic components. An insulating plastic material layer (not shown in the figure), such as Mylar, can be used to be located between the key cap 102 and the switch component 104 to obstruct the electrostatic charge transfer from the body of the user into the electronic apparatus 100.
The conventional obstructing method is still not a fundamental solution. When the quantity of electrostatic charge has accumulated to a certain level, the plastic may be unable to obstruct further electrostatic charge, allowing a great quantity of charge to flash in a short time to damage the electronic component 108. Therefore, an electronic apparatus which is able to fundamentally prevent the damage caused by electrostatic charge is needed in practice.